The nutrient value of 43 garden crops has declined in recent decades, a study led by a University of Texas biochemist shows. The most likely explanation seems to be that farmers have planted varieties that emphasize other traits, such as greater yield, resistance to pests and adaptability to different climates, said Donald Davis of UT's Biochemical Institute. "Emerging evidence suggests that when you select for yield, crops grow bigger and faster but they don't necessarily have the ability to make or uptake nutrients at the same, faster rate," he said. Davis and researchers at the Bio-Communications Research Institute in Wichita, Kan., studied mostly vegetables, but also melons and strawberries, for which nutritional information was available from 1950 and 1999. Their findings will appear in the December issue of the Journal of the American College of Nutrition. The results suggest a need for research into other nutrients and foods, such as grains, legumes, meat, milk and eggs, Davis said.